[patch] Fix failing nested-3.C on ARM.

[Richard Earnshaw]

The regexp in nested-3.C has to parse the machine-specific comment
character; on ARM that is '@'.

Tested on arm-eabi, where this test now passes.

OK?

R.

        * g++.dg/debug/dwarf2/nested-3.C: Add ARM comment character to regexp.

--- g++.dg/debug/dwarf2/nested-3.C      (revision 188750)
+++ g++.dg/debug/dwarf2/nested-3.C      (local)
@@ -59,4 +59,4 @@ main ()
 //
 //     Hence the scary regexp:
 //
-//     { dg-final { scan-assembler "\[^\n\r\]*\\(DIE \\(0x(\[0-9a-f\]+)\\) 
DW_TAG_namespace\\)\[\n\r\]+\[^\n\r\]*\"thread\[\^\n\r]+\[\n\r\]+(\[^\n\r\]*\[\n\r\]+)+\[^\n\r\]*\\(DIE
 \\(0x(\[0-9a-f\]+)\\) 
DW_TAG_class_type\\)(\[\n\r\]+\[^\n\r\]*)+\"Executor\[^\n\r\]+\[\n\r\]+\[^\n\r\]*DW_AT_declaration\[\n\r\]+\[^\n\r\]*DW_AT_signature\[^#/!|\]*\[#/!|\]
 
\[^\n\r\]*\\(DIE\[^\n\r\]*DW_TAG_subprogram\\)\[\n\r\]+(\[^\n\r\]*\[\n\r\]+)+\[^\n\r\]*\"CurrentExecutor\[^\n\r\]+\[\n\r\]+(\[^\n\r\]*\[\n\r\]+)+(\[^\n\r\]*\[\n\r\]+)+\[^\n\r\]*end
 of children of DIE 0x\\3\[\n\r]+\[^\n\r\]*end of children of DIE 
0x\\1\[\n\r]+" } }
+//     { dg-final { scan-assembler "\[^\n\r\]*\\(DIE \\(0x(\[0-9a-f\]+)\\) 
DW_TAG_namespace\\)\[\n\r\]+\[^\n\r\]*\"thread\[\^\n\r]+\[\n\r\]+(\[^\n\r\]*\[\n\r\]+)+\[^\n\r\]*\\(DIE
 \\(0x(\[0-9a-f\]+)\\) 
DW_TAG_class_type\\)(\[\n\r\]+\[^\n\r\]*)+\"Executor\[^\n\r\]+\[\n\r\]+\[^\n\r\]*DW_AT_declaration\[\n\r\]+\[^\n\r\]*DW_AT_signature\[^#/!|@\]*\[#/!|@\]
 
\[^\n\r\]*\\(DIE\[^\n\r\]*DW_TAG_subprogram\\)\[\n\r\]+(\[^\n\r\]*\[\n\r\]+)+\[^\n\r\]*\"CurrentExecutor\[^\n\r\]+\[\n\r\]+(\[^\n\r\]*\[\n\r\]+)+(\[^\n\r\]*\[\n\r\]+)+\[^\n\r\]*end
 of children of DIE 0x\\3\[\n\r]+\[^\n\r\]*end of children of DIE 
0x\\1\[\n\r]+" } }